Listen again to Farming TodayFarming Today: There has been a lot of talk about vaccination, not least here on Farming Today. The government has again ruled it out for the moment but there are those who maintain that these new cases on farms near Egham wouldn't have happened had DEFRA vaccinated at the time of the first outbreak. Dr Colin Fink is a virologist at Warwick University and I asked him if he was surprised that the disease hadn't been spotted in these animals

Colin Fink:Foot and Mouth disease is often not clinically obvious in sheep and what it does say is that the virus has travelled far further- unsurprisingly - than the original DEFRA expectation and this is why back in August I said that now was the time to ring vaccinate so that there would be no susceptible animals within quite a wide range. It's arguable how far out you have to vaccinate but that would have meant that the animals would not have been susceptible and the disease would have died out. Now I think we have a major problem because without the sunshine to destroy the virus in the field we're going to have virus around for a long time

Farming Today:How concerned are you that now the virus will be in the wildlife population?

Colin Fink:It's possible. Not only in the wildlife population which is one problem but it will be in what are called fomites - it will be in the fields it will be in the mud in the slurry and that's a much more difficult problem to eliminate and it will survive for a very long time in cool conditions in this sort of material and so now it's out there it is well entrenched and the chance of other animals picking it up and it then getting into the wildlife also increase day by day. The longer they wait and vacillate about vaccination the more this is going to become entrenched...

Farming Today: But we can't vaccinate the wildlife population...

Colin Fink: ..No but for any vaccine to be successful you only have to vaccinate about 70% of the susceptible population and then it will die out